A Pediatric Case of Blau Syndrome with NOD2 p.Arg587Cys Mutation Successfully Managed with Infliximab: A Long-Term...

To describe the long-term ocular and systemic course of a pediatric patient with Blau syndrome carrying aNOD2p.Arg587Cys mutation, and to report the therapeutic response to infliximab after inadequate disease control with adalimumab.

Single-case report of a girl with genetically confirmed Blau syndrome managed at a tertiary referral center for pediatric uveitis in Japan. Clinical findings, multimodal imaging, treatment course, and long-term outcomes were reviewed from infancy through late childhood. Ocular inflammation was assessed by slit-lamp biomicroscopy, fundus examination, fluorescein angiography, and optical coherence tomography. Systemic therapy comprised methotrexate and tumor necrosis factor-alpha (TNF-α) inhibitors.

The patient developed recurrent fever and urticaria-like rash at 7months of age, followed by bilateral granulomatous uveitis with optic disc edema at 9months. Genetic testing at 14months identified a heterozygousNOD2p.Arg587Cys mutation, confirming Blau syndrome. Methotrexate combined with adalimumab achieved only partial control: ocular inflammation recurred despite normalization of C-reactive protein and erythrocyte sedimentation rate, and recurrent hypopyon developed even after dose escalation to the standard pediatric maximum. After switching to infliximab at 4years and 6months of age, sustained remission was maintained for more than four years, with stable visual acuity, stable intraocular pressure, and no further ocular or systemic relapses.

In this patient, systemic inflammatory markers did not reliably reflect intraocular disease activity, and infliximab achieved durable remission of Blau-associated uveitis refractory to adalimumab. Although limited to a single observation, the long-term outcome supports infliximab as a salvage option in refractory pediatric Blau-associated uveitis and underscores the value of ophthalmologic-rather than serological-monitoring of disease activity.